Hitachi Energy RET670 Transformer Protection IED Unit

Module Feature

RET670 belongs to Hitachi Energy Relion 670 high-end protection family.

It supports two-winding, three-winding, autotransformer, phase-shifting transformer and shunt reactor applications. It adopts adaptive differential algorithm with harmonic restraint, stable against magnetizing inrush and over-excitation. It integrates breaker failure, restricted earth fault, overfluxing, overcurrent, voltage protection and tap-changer control. It supports IEC61850, GOOSE, DNP3 and IEC 60870-5-103, widely used in power plant step-up bays, transmission and sub-transmission substations.

Working principle

The IED collects synchronized current signals from all CT sets of transformer windings.

When internal fault occurs, differential current exceeds threshold and triggers fast trip to open associated breakers. It records COMTRADE fault waveforms, time-stamped event logs and thermal load data, and uploads real-time measurements and alarms to SCADA system.

Onboard components

Main CPU board, analog CT/PT sampling module, local HMI panel, binary input/output matrix, Ethernet communication module, DC auxiliary power supply unit.

LED indicators

Front LEDs indicate power status, healthy running state, trip signal and communication fault alarm.

Hardware self‑diagnosis

Continuous supervision detects CT circuit break, VT fuse failure, internal hardware anomaly, temperature over-limit and communication interruption, fault codes are shown on local HMI.

Programming software

Hitachi Energy PCM600, used for protection setting, bay logic configuration, fault waveform analysis and firmware upgrade.

Electrical & Process Parameters

Model:RET670 Brand:Hitachi Energy (Former ABB) Device type:Transformer protection and control IED Auxiliary supply:88–264V DC / 85–264V AC CT input:1A / 5A Function:Transformer differential, backup protection, tap-changer control and fault recording

Mechanical & Structure

Mounting:Panel cutout or 19-inch rack mounting

Protection class:IP20

Housing:Metal relay enclosure

Environmental

Operating temperature:-25℃ ~ +55℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:CE, IEC, UL

Status:Original Hitachi Energy substation protection spare

Installation

Install IED in protection panel, connect CT/VT wiring, auxiliary supply and network cable.

Check CT polarity, perform differential stability test and GOOSE interlock verification before energizing.

Interface

CT/PT analog terminals, binary I/O terminals, Ethernet communication port, rear expansion slot.

Diagnostic

Differential unstable: Wrong CT polarity, open CT wiring or saturation issue. Breaker failure alarm: Circuit breaker fails to open after trip command. Communication offline: Network configuration error or damaged network cable.

Product Brief

Hitachi Energy RET670 Relion 670 IED, adaptive differential protection relay for substation power transformer bay protection and control replacement.